From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=217.140.110.172 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793881958; b=I2WrsmuWldwtcMnpjwC7+LgVv3WU+MeFDUHAEwRisdoMxUeGhVDZSbGR9AHCQRCXQ1np pz3k1Tz0pXkwLSdTbmMKXILTJ4ABvV1C0mMbNASKsh0Ngsy00p/rfzsuJeX9sINYPaLrI DyahuhIe49C3hvY9PVCBzexlIB3CGKEaeHY8NFkQYK3x2W47qJHUElDwzYDLkygcsPLlf FvvekxG1xeWe6pFdJTIO84XKTv2PvQpB7dkVhxrcphD5lWbRysU2CCkJ2FBhHpTfMq8hB mU36gQWREpQ25vjjBaSDo8D0mcBr0zjn/H9fQ+wem8s5vuY0mnkdf09YiQfEJe1Z0FQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793881958; h=DMARC-Filter:Received:Received:DKIM-Signature:Message-ID:Date: MIME-Version:User-Agent:Subject:To:Cc:References:Content-Language: From:In-Reply-To:Content-Type:Content-Transfer-Encoding; bh=DyTF3dyvS5SSGFIBcrhN4ZmURkgy5Sbn/dGYPAONXqM=; b=2+FPnXg2AgipicRlpYqD8I/gFoCGj9MF+hZauCwcaE+Ip5GqeJIzssiKo5CPS6MO/jMz uFzWeDA9qe/yfXOC9ly2GDTViFQe5lJ+3tO0M8OMZVuG7FxrDnOc7JTuAd1za49CfT4E4 Vw0TsqENOX6jY3iBmptsDqn3w/PAed/DoA6gFk+DQQ8lk7+K0CJCE+mIHUinm+BZB+TL3 5nJsr+bMPoP68eNFNY/68b+K/IDstXYc/YfOhRD9zRWw4QZtLNe9H5iHICzWADMbB6dwr fQCbM+qN0sbqVJUTejZQJwdazmt9qWp3+0x4iAqcLBpgrXkOBQGtafIxRSLh1lAIPrw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=XUuW51sz; arc=none smtp.remote-ip=217.140.110.172 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6F766606A326; Thu, 5 Nov 2026 12:32:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 6F766606A326 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=XUuW51sz Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7E6DB1516; Thu, 5 Nov 2026 04:32:33 -0800 (PST) Received: from [10.2.197.99] (ewhatever.cambridge.arm.com [10.2.197.99]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 844DC3F673; Thu, 5 Nov 2026 04:32:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1793881956; bh=sOJfsNiRaIqkJeRVq2myKYTsgRpSmfg+roVcJPV2SFA=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=XUuW51szJyTqemAxFw9UWx4FPuqHfs88Ikvh66VJhCpcBQt3c+fn7CcTW4XtPaeuJ sZwL9KFCcEgGbpwIHdaCDgak2PeLSLGCPHXRs8p+towqG1qJGhUyDuxxySnrMUDTAH Tyg63Z30AWsRJLHyVUHMN69JnMGqwEyx2pScawsc= Message-ID: <55e1da04-1e8b-4783-a4db-0f154d8ec10e@arm.com> Date: Thu, 5 Nov 2026 12:32:33 +0000 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v16 2/7] qcom-tgu: Add TGU driver To: Songwei Chai , andersson@kernel.org, alexander.shishkin@linux.intel.com, mike.leach@linaro.org, konrad.dybcio@oss.qualcomm.com, james.clark@arm.com, krzk+dt@kernel.org, conor+dt@kernel.org Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, coresight@lists.linaro.org, devicetree@vger.kernel.org, gregkh@linuxfoundation.org, Jie Gan References: <20260730080704.2903540-1-songwei.chai@oss.qualcomm.com> <20260730080704.2903540-3-songwei.chai@oss.qualcomm.com> Content-Language: en-US From: Suzuki K Poulose In-Reply-To: <20260730080704.2903540-3-songwei.chai@oss.qualcomm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 30/07/2026 09:06, Songwei Chai wrote: > Add driver to support device TGU (Trigger Generation Unit). > TGU is a Data Engine which can be utilized to sense a plurality of > signals and create a trigger into the CTI or generate interrupts to > processors. Add probe/enable/disable functions for tgu. > > Signed-off-by: Songwei Chai > Acked-by: Konrad Dybcio > Reviewed-by: Jie Gan > --- > .../ABI/testing/sysfs-bus-amba-devices-tgu | 9 + > MAINTAINERS | 11 + > drivers/Makefile | 1 + > drivers/hwtracing/Kconfig | 2 + > drivers/hwtracing/qcom/Kconfig | 20 ++ > drivers/hwtracing/qcom/Makefile | 3 + > drivers/hwtracing/qcom/tgu.c | 192 ++++++++++++++++++ > drivers/hwtracing/qcom/tgu.h | 51 +++++ > 8 files changed, 289 insertions(+) > create mode 100644 Documentation/ABI/testing/sysfs-bus-amba-devices-tgu > create mode 100644 drivers/hwtracing/qcom/Kconfig > create mode 100644 drivers/hwtracing/qcom/Makefile > create mode 100644 drivers/hwtracing/qcom/tgu.c > create mode 100644 drivers/hwtracing/qcom/tgu.h > > diff --git a/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu b/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu > new file mode 100644 > index 000000000000..36ab64f1e301 > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu > @@ -0,0 +1,9 @@ > +What: /sys/bus/amba/devices//enable_tgu > +Date: August 2026 > +KernelVersion: 7.2 > +Contact: Jinlong Mao , Songwei Chai > +Description: > + (RW) Set/Get the enable/disable status of TGU > + Accepts only one of the 2 values - 0 or 1. > + 0 : disable TGU. > + 1 : enable TGU. > diff --git a/MAINTAINERS b/MAINTAINERS > index ce5c5185c773..4789321cca6d 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -22360,6 +22360,17 @@ S: Maintained > F: Documentation/tee/qtee.rst > F: drivers/tee/qcomtee/ > > +QUALCOMM HARDWARETRACING DRIVER > +M: Songwei Chai > +M: Jie Gan > +M: Suzuki K Poulose > +L: linux-arm-msm@vger.kernel.org > +S: Maintained > +T: git git://git.kernel.org/pub/scm/linux/kernel/git/coresight/linux.git > +F: Documentation/ABI/testing/sysfs-bus-amba-devices-tgu > +F: Documentation/devicetree/bindings/arm/qcom,tgu.yaml > +F: drivers/hwtracing/qcom/ > + > QUALCOMM TRUST ZONE MEMORY ALLOCATOR > M: Bartosz Golaszewski > L: linux-arm-msm@vger.kernel.org > diff --git a/drivers/Makefile b/drivers/Makefile > index 0841ea851847..6a2cbe5b340f 100644 > --- a/drivers/Makefile > +++ b/drivers/Makefile > @@ -176,6 +176,7 @@ obj-$(CONFIG_RAS) += ras/ > obj-$(CONFIG_USB4) += thunderbolt/ > obj-$(CONFIG_CORESIGHT) += hwtracing/coresight/ > obj-y += hwtracing/intel_th/ > +obj-y += hwtracing/qcom/ > obj-$(CONFIG_STM) += hwtracing/stm/ > obj-$(CONFIG_HISI_PTT) += hwtracing/ptt/ > obj-y += android/ > diff --git a/drivers/hwtracing/Kconfig b/drivers/hwtracing/Kconfig > index 911ee977103c..8a640218eed8 100644 > --- a/drivers/hwtracing/Kconfig > +++ b/drivers/hwtracing/Kconfig > @@ -7,4 +7,6 @@ source "drivers/hwtracing/intel_th/Kconfig" > > source "drivers/hwtracing/ptt/Kconfig" > > +source "drivers/hwtracing/qcom/Kconfig" > + > endmenu > diff --git a/drivers/hwtracing/qcom/Kconfig b/drivers/hwtracing/qcom/Kconfig > new file mode 100644 > index 000000000000..5c94c75ffa39 > --- /dev/null > +++ b/drivers/hwtracing/qcom/Kconfig > @@ -0,0 +1,20 @@ > +# SPDX-License-Identifier: GPL-2.0-only > +# > +# QCOM specific hwtracing drivers > +# > +menu "Qualcomm specific hwtracing drivers" > + > +config QCOM_TGU > + tristate "QCOM Trigger Generation Unit driver" > + depends on ARCH_QCOM || COMPILE_TEST > + depends on ARM_AMBA > + help > + This driver provides support for Trigger Generation Unit that is > + used to detect patterns or sequences on a given set of signals. > + TGU is used to monitor a particular bus within a given region to > + detect illegal transaction sequences or slave responses. It is also > + used to monitor a data stream to detect protocol violations and to > + provide a trigger point for centering data around a specific event > + within the trace data buffer. > + > +endmenu > diff --git a/drivers/hwtracing/qcom/Makefile b/drivers/hwtracing/qcom/Makefile > new file mode 100644 > index 000000000000..5a0a868c1ea0 > --- /dev/null > +++ b/drivers/hwtracing/qcom/Makefile > @@ -0,0 +1,3 @@ > +# SPDX-License-Identifier: GPL-2.0 > + > +obj-$(CONFIG_QCOM_TGU) += tgu.o > diff --git a/drivers/hwtracing/qcom/tgu.c b/drivers/hwtracing/qcom/tgu.c > new file mode 100644 > index 000000000000..9c7dd4a09f02 > --- /dev/null > +++ b/drivers/hwtracing/qcom/tgu.c > @@ -0,0 +1,192 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "tgu.h" > + > +static void tgu_write_all_hw_regs(struct tgu_drvdata *drvdata) > +{ > + TGU_UNLOCK(drvdata->base); > + /* Enable TGU to program the triggers */ > + writel(1, drvdata->base + TGU_CONTROL); > + TGU_LOCK(drvdata->base); > +} > + > +static void tgu_enable(struct tgu_drvdata *drvdata) > +{ > + tgu_write_all_hw_regs(drvdata); > + drvdata->enabled = true; > +} > + > +static void tgu_disable(struct tgu_drvdata *drvdata) > +{ > + TGU_UNLOCK(drvdata->base); > + writel(0, drvdata->base + TGU_CONTROL); > + TGU_LOCK(drvdata->base); > + > + drvdata->enabled = false; > +} > + > +static ssize_t enable_tgu_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct tgu_drvdata *drvdata = dev_get_drvdata(dev); > + bool enabled; > + > + scoped_guard(mutex, &drvdata->lock) > + enabled = drvdata->enabled; > + > + return sysfs_emit(buf, "%d\n", enabled); > +} > + > +/* enable_tgu_store - Enable or disable the Trigger Generation Unit (TGU). */ > +static ssize_t enable_tgu_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, > + size_t size) > +{ > + struct tgu_drvdata *drvdata = dev_get_drvdata(dev); > + unsigned long val; > + int ret; > + > + ret = kstrtoul(buf, 0, &val); > + if (ret || val > 1) > + return -EINVAL; > + > + /* > + * Hold the mutex across the whole check-and-act sequence: the check of > + * drvdata->enabled, the PM runtime reference counting and the state > + * update must be atomic, otherwise concurrent writers could each > + * imbalance the PM runtime usage counter. > + */ > + guard(mutex)(&drvdata->lock); > + > + if (val) { > + if (drvdata->enabled) > + return -EBUSY; > + > + ret = pm_runtime_resume_and_get(dev); > + if (ret) > + return ret; > + > + tgu_enable(drvdata); > + } else { > + if (!drvdata->enabled) > + return -EINVAL; > + > + tgu_disable(drvdata); > + pm_runtime_put(dev); > + } > + > + return size; > +} > +static DEVICE_ATTR_RW(enable_tgu); > + > +static struct attribute *tgu_common_attrs[] = { > + &dev_attr_enable_tgu.attr, > + NULL, > +}; > + > +static const struct attribute_group tgu_common_grp = { > + .attrs = tgu_common_attrs, > +}; > + > +static const struct attribute_group *tgu_attr_groups[] = { > + &tgu_common_grp, > + NULL, > +}; > + > +static int tgu_probe(struct amba_device *adev, const struct amba_id *id) > +{ > + struct device *dev = &adev->dev; > + struct tgu_drvdata *drvdata; > + int ret; > + > + drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); > + if (!drvdata) > + return -ENOMEM; > + > + drvdata->dev = &adev->dev; > + dev_set_drvdata(dev, drvdata); > + > + drvdata->base = devm_ioremap_resource(dev, &adev->res); > + if (IS_ERR(drvdata->base)) > + return PTR_ERR(drvdata->base); > + > + ret = devm_mutex_init(dev, &drvdata->lock); > + if (ret) > + return ret; > + > + drvdata->enabled = false; > + > + ret = sysfs_create_groups(&dev->kobj, tgu_attr_groups); > + if (ret) { > + dev_err(dev, "failed to create sysfs groups: %d\n", ret); > + return ret; > + } > + > + pm_runtime_put(&adev->dev); > + > + return 0; > +} > + > +static void tgu_remove(struct amba_device *adev) > +{ > + struct device *dev = &adev->dev; > + struct tgu_drvdata *drvdata = dev_get_drvdata(dev); > + > + sysfs_remove_groups(&dev->kobj, tgu_attr_groups); > + > + /* > + * If the device is still enabled through sysfs, disable the hardware > + * and drop the PM runtime reference taken in enable_tgu_store() so the > + * usage counter stays balanced. Use the synchronous put: the driver core > + * disables runtime PM right after ->remove() returns, and the barrier in > + * pm_runtime_disable() would cancel a still-queued async idle/suspend, > + * leaving the runtime-PM state inconsistent. > + */ > + scoped_guard(mutex, &drvdata->lock) { > + if (drvdata->enabled) { > + tgu_disable(drvdata); > + pm_runtime_put_sync(dev); > + } > + } > +} > + > +static const struct amba_id tgu_ids[] = { > + { > + .id = 0x000f0e00, > + .mask = 0x000fffff, > + }, > + { 0, 0, NULL }, > +}; > + > +MODULE_DEVICE_TABLE(amba, tgu_ids); > + > +static struct amba_driver tgu_driver = { > + .drv = { > + .name = "qcom-tgu", > + .suppress_bind_attrs = true, > + }, > + .probe = tgu_probe, > + .remove = tgu_remove, > + .id_table = tgu_ids, > +}; > + > +module_amba_driver(tgu_driver); > + > +MODULE_AUTHOR("Songwei Chai "); > +MODULE_AUTHOR("Jinlong Mao "); > +MODULE_DESCRIPTION("Qualcomm Trigger Generation Unit driver"); > +MODULE_LICENSE("GPL"); > diff --git a/drivers/hwtracing/qcom/tgu.h b/drivers/hwtracing/qcom/tgu.h > new file mode 100644 > index 000000000000..ebba49402a20 > --- /dev/null > +++ b/drivers/hwtracing/qcom/tgu.h > @@ -0,0 +1,51 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. > + */ > + > +#ifndef _QCOM_TGU_H > +#define _QCOM_TGU_H > + > +/* Register addresses */ > +#define TGU_CONTROL 0x0000 > +#define TGU_LAR 0xfb0 > +#define TGU_UNLOCK_OFFSET 0xc5acce55 > + > +static inline void TGU_LOCK(void __iomem *addr) > +{ > + do { > + /* Wait for things to settle */ > + mb(); > + writel_relaxed(0x0, addr + TGU_LAR); > + } while (0); > +} This is simply replicating the CS_LOCK/CS_UNLOCK. I don't mind those (and relevant definitions) to be moved into include/linux/coresight.h and reused for your driver. The rest looks fine by me. Suzuki > + > +static inline void TGU_UNLOCK(void __iomem *addr) > +{ > + do { > + writel_relaxed(TGU_UNLOCK_OFFSET, addr + TGU_LAR); > + /* Make sure everyone has seen this */ > + mb(); > + } while (0); > +} > + > +/** > + * struct tgu_drvdata - Data structure for a TGU (Trigger Generation Unit) > + * @base: Memory-mapped base address of the TGU device > + * @dev: Pointer to the associated device structure > + * @lock: Mutex serialising enable/disable and the associated PM runtime > + * reference counting against concurrent sysfs access > + * @enabled: Flag indicating whether the TGU device is enabled > + * > + * This structure defines the data associated with a TGU device, > + * including its base address, device pointer, the lock serialising > + * enable/disable, and the enable status. > + */ > +struct tgu_drvdata { > + void __iomem *base; > + struct device *dev; > + struct mutex lock; > + bool enabled; > +}; > + > +#endif